This required to add two functions down the stack to uart.c and ra.sci.c.
- One for telling, whther the transmission is busy.
- One for reporting the size of the TX buffer.
Tested with a EK-RA6M2 board.
* `init()` can be called multiple times to reconfigure UART.
* After `deinit()` it is impossible to call `init()` again.
Signed-off-by: Tomasz 'CeDeROM' CEDRO <tomek@cedro.info>
This enables optional support for the hardware UART to use the RTS and/or
CTS pins for flow control.
The new "flow" constructor keyword specifies a bitmask of RTS and/or CTS.
This matches the interface used by machine.UART on stm32 and rp2.
Previously on ESP32 it was possible to specify which pins to use for the
RTS and CTS signals, but hardware flow control was never functional: CTS
was not checked before transmitting bytes, and RTS was always driven high
(signalling no buffer space available). With this patch, CTS and RTS both
operate as expected.
This also includes an update to the machine.UART documentation.
Signed-off-by: Will Sowerbutts <will@sowerbutts.com>
Latest versions of Sphinx (at least 3.1.0) do not need the `*` escaped and
will render the `\` in the output if it is there, so remove it.
Fixes issue #6209.
The UART.init() method is now included unconditionally and its wording
adjusted to better describe ports other than the cc3200.
UART.irq() is also included unconditionally, but this is currently only
available on the WiPy target.
